The present invention relates to machinery used in the application of gassing valves to end closures and in pressurized dispensers.
Pressurized dispensers, commonly referred to as aerosol dispensers, maintain a product to be dispensed under the pressure of a propellant. The propellant is discharged into the dispenser in an operation called in the art "gassing." One form of gassing is through a valve on an end closure of the dispenser. The valve passes propellant into the dispenser but does not permit propellant to escape.
One type of gassing valve is described in the U.S. Pat. No. 3,880,332 to Merle G. Risdon.
The Risdon valve is a flap valve with a backing of resilient material and a layer of adhesive. The resilient material may be Mylar. The backing and adhesive are coextensive. Only a preselected portion of the adhesive is activated and bonded to the end closure. The balance of the adhesive serves to seal against an inside surface of the end closure and prevents propellant leakage. A vent slot is formed in this valve to prevent excessive spreading of the solvent used in activation of the adhesive.
This specification is directed to an apparatus for applying flap or face sealing valves of the general type disclosed in the Risdon patent to end closures.